1. Field of the Invention
The present invention relates generally to inductor structures employed within microelectronic fabrications. More particularly, the present invention relates to planar spiral inductor structures employed within microelectronic fabrications.
2. Description of the Related Art
Microelectronic fabrications are fabricated from microelectronic substrates over which are formed patterned microelectronic conductor layers which are separated by microelectronic dielectric layers.
As microelectronic fabrication integration levels and functionality levels have increased, it has become common in the art of microelectronic fabrication to employ in addition to the generally conventional microelectronic device structures such as but not limited to transistor structures, resistor structures, diode structures and capacitor structures when fabricating microelectronic fabrications, less conventional microelectronic device structures such as inductor structures when fabricating microelectronic fabrications. In particular, within microelectronic fabrications which are intended to be employed within high frequency microelectronic fabrication applications, such as mobile communications high frequency microelectronic fabrication applications, it is often common to employ microelectronic inductor structures, in particular in conjunction with microelectronic capacitor structures, within those microelectronic fabrications.
While microelectronic inductor structures are thus desirable and often essential within the art of microelectronic fabrication, microelectronic inductor structures are nonetheless not entirely without problems in the art of microelectronic fabrication. In that regard, it is typically desirable in the art of microelectronic fabrication, but nonetheless not always readily achievable in the art of microelectronic fabrication, to fabricate microelectronic fabrications having formed therein microelectronic inductor structures with optimal properties, as characterized by enhanced Q values of the microelectronic inductor structures.
It is thus towards the goal of fabricating within microelectronic fabrications microelectronic inductor structures with optimal properties of the microelectronic inductor structures, as characterized by enhanced Q values of the microelectronic inductor structures, that the present invention is directed.
Various microelectronic inductor structures having desirable properties, including but not limited to enhanced Q values, have been disclosed in the art of microelectronic fabrication.
For example, Ashby et al., in “High Q Inductors for Wireless Applications in a Complementary Silicon Bipolar Process,” IEEE J. of Solid State Circuits, Vol. 31(1), January 1996, pp. 4-9, discloses a planar spiral inductor structure fabricated with a particularly enhanced Q value for use within a microelectronic fabrication. To realize the foregoing object, there is employed when fabricating the planar spiral inductor structure a substrate of higher substrate resistance and a spirally patterned conductor layer of lower series resistance.
In addition, Kitahara, in U.S. Pat. No. 5,977,845 discloses a microelectronic inductor structure in conjunction with a microelectronic capacitor structure for use within a microelectronic fabrication, where there is avoided within the microelectronic inductor structure in conjunction with the microelectronic capacitor structure for use within the microelectronic fabrication a magnetic field effect upon the microelectronic capacitor structure as induced by the microelectronic inductor structure within the microelectronic fabrication. To realize the foregoing object, the microelectronic inductor structure comprises a pair of spiral inductor structures disposed geometrically with respect to the microelectronic capacitor structure such that a pair of magnetic fields generated by the pair of spiral inductor structures is equivalent, anti-parallel and cancels with respect to the microelectronic capacitor structure.
Finally, Yamazaki et al., in U.S. Pat. No. 6,002,161, also discloses a planar spiral inductor structure fabricated with an enhanced Q value for use within a microelectronic fabrication. To realize the foregoing object, there is decreased when fabricating the planar spiral inductor structure a series resistance of a spirally patterned conductor layer employed within the planar spiral inductor structure by employing within various portions of the spirally patterned conductor layer employed within the planar spiral inductor structure an additional laminated conductor layer which is insularly configured with respect to the spirally patterned conductor layer.
The teachings of the foregoing disclosures are incorporated herein fully by reference.
Desirable in the art of microelectronic fabrication are additional methods and materials which may be employed for fabricating within microelectronic fabrications microelectronic inductor structures with optimal properties, as characterized by enhanced Q values of the microelectronic inductor structures.
It is towards the foregoing object that the present invention is directed.